The ad says Portman helped create jobs outside the U.S. via pro-trade policies throughout his political career, sending opportunities to Central America, Mexico and China. The ad will be played on both cable and broadcast television in Toledo, Dayton, Columbus and Cleveland.

Trade will play a central role this election in the Midwest state known for its manufacturing jobs. It's already a big issue atop the ticket, where both Democratic presidential candidates Sen. Bernie Sanders, I-Vt., and Hillary Clinton have come out against the recently negotiated Trans-Pacific Partnership. And Donald Trump has made opposition to free trade a major part of his campaign.

Portman's Democratic opponent, former Gov. Ted Strickland, has stated his opposition to the 12-nation trade deal. Portman, who previously served as U.S. Trade Representative, has said he does not support the TPP in its current form.

A release from Senate Majority PAC said the new campaign is its first television advertising in Ohio. The group already spent $4,500 toward the Ohio Senate race this year, according to OpenSecrets.org. The conservative PAC Americans For Prosperity, part of the Koch Brothers network, is the outside group with the most dollars in the race, spending more than $1.5 million so far.